In an automation line having an industrial robot introduced therein, if the robot is stopped by a malfunction or the like and control becomes impossible, it is necessary to repair the robot urgently and start the operation again. However, where it is difficult to accomplish restoration in a short time, it is necessary to withdraw the stopped robot from the line and continue the operation of the line without using the robot.
Where stopping of the robot is due to an electrical fault in a control device, a driving circuit of a driving motor or the like, since a rotary operation portion such as an arm of the robot is not electrically moved, in order to withdraw the robot, it is necessary to move the rotary operating portion mechanically by hand. In general, however, since a brake device is built-into a motor for driving the rotary operating portion of the robot to brake an output shaft of the motor when the motor is stopped, it is very difficult to manually move the rotary operating porting of the stopped robot.